Pilot burner-thermoelectric generator assembly



June 12, 1962 c. E. HAJNY 3,038,950

PILOT BURNER-THERMOELECTRIC GENERATOR ASSEMBLY Filed March 11, 1960. 2 Sheets-Sheet 1 INVEN TOR. CHARLES E. HAJNY BY 9 QM ATJ'ORNjY C. E. HAJNY June 12, 1962 PILOT BURNER-THERMOELECTRIC GENERATOR ASSEMBLY Filed March 11, 1960 INVENTOR. CHARLES E. HAJNY ATTORNEY I BY dd, 6.

United States Patent 3,038,950 PILOT BURNER-THERMOELECTRI GENERATOR ASSEMBLY Charles E. Hajny, Milwaukee, Wis, assignor, by mesne assignments, to Penn Controls, Inc, Goshen, Ind, a corporation of Indiana Filed Mar. 11, 1960, Ser. No. 14,346 6 Claims. (Cl. 136-4) This invention relates to improvements in pilot burnerthermoelectric generator assemblies and more particularly to assemblies of this type characterized by low fuel consumption and non-aerated operation.

Developments inthe field of control systems for gaseous fuel burning appliances have been in the direction of increasing employment of low consumption, constant burning pilot burner-thermoelectric generator assemblies. Because of the small volume of gaseous fuel consumed, this type of pilot-generator lends itself to non-aerated operation, i.e., operation without mixture of gas and primary air Within the burner prior to emission from a flame port, and it can also be relatively small in size. Pilotgenerators of this type are not without problems, however, as demonstrated by the fact that certain of the presently available pilot generators are markedly affected by cycling on and off of the main burner with which it is associated. Certain prior art low consumption pilot generators are of the concentric type and are susceptible to failure of the gas seals thereof, permitting the gaseous fuel to attack the Copel inner thermoelement with the result that said thermoelement rapidly deteriorates. The concentric pilot-generators have the further disadvantage that they are operable in a vertical position only, and are not adaptable for use in confined horizontal spaces such as range ovens or the like.

With the above in mind it is a general object of the present invention to provide an improved unitary low consumption pilot burner-thermoelectric generator assembly which is so constructed that proper igniting relation of the pilot burner thereof with an associated main burner permits disposition of the generator thereof in an operative position in which it is not subject to impingement by the main burner flame, the output of said generator thus being substantially unaffected by cycling of the main burner.

A further object of the invention is to provide an improved pilot-generator of the aforementioned character in' which the generator and burner thereof are disposed in spaced, side by side relation, permitting isolation of the generator from the burner gaseous fuel passage without the use of concentric gas seals of the type required in concentric pilot-generator structures.

Another object of the invention is to provide an im proved pilot-generator of the class described one form of which is of horizontal and another form of which is of vertical orientation.

Still another object of the invention is to provide an improved pilot-generator as aforedescribed which utilizes a novel heat conductive member operable to perform the dual functions of flame shaping means for the burner and heat probe'means for the generator.

Another object of the invention is to provide an improved pilot-generator as aforementioned which is charact'eriz'e'dby its simplicity and compactness of constructioii its efi'lciency of operation, andits adaptability to fabrication by inexpensive mass production techniques.

Other and further objects and advantages of the inventi o'rihwill' beotne apparent as the description proceeds, reference being had to the accompanying drawing in ic FIGURE 1 is a vertical sectional view of a vertical type ice pilot-generator assembly constructed in accordance with the principles of the present invention;

FIGURE 2 is a plan view of the pilot generator assembly of FIGURE 1 taken along the line lL-II;

FIGURE 3 is a vertical sectional view of a horizontal type generator constructed in accordance with the principles of the present invention; and

FIGURE 4 is a fragmentary plan view taken approxlmately along the line IVIV in FIGURE 3.

Referring now to FIGURES l and 2 of the drawing, the improved pilot generator illustrated therein is indicated by the numeral 5 and comprises a pilot burner 26 and a thermocouple 27. The assembly 5 is mounted in with the burner in igniting relation with a main burner fragmentarily shown at 6. The assembly 5 comprises a supporting block 7 formed with a bore 8 therethrough in which a tubular outer thermoelement 9, for example of stainless steel, is sealingly telescoped, as by brazing. Extending in spaced coaxial relation within the outer thermoelement 9 is a rod-like inner thermoelement 10, for example of C-opel. The elements 9 and 10 are electrically joined at their outer ends by a welded bead 11 which also seals the outer end of the tubular outer element 9 and forms the hot junction for the thermocouple 27. The annular space between the inner element 10 and outer element 9 at the inner ends thereof is filled by an annular layer of electrical insulation 12. A thermocouple lead 13 has an outer tubular conductor 14 sealingly telescoped int-o the opposite end of the bore 8, as by silver soldering, and also has an insulated inner conductor 15 which is electrically connected to the adjacent end of the inner thermoelement 10, as by resistance welding. The lead 13 is provided at its free end with suitable connecto-r means (not shown) for connecting the thermocouple 27 to a load.

The block 7 is also formed with a bore 16, formed with a counterbore 17 into which one end of a tubular burner body 18 is sealingly teleseoped, as by brazing. The opposite end of the bore 16 intersects an internally threaded socket 28 formed in the block 7 and adapted to receive complementary fuel supply fittings. The burner body :18 is tubular and terminates at its upper end in a reduced diameter portion forming a fuel discharge orifice 19. The axis of the burner body 18 is substantially parallel with that of the thermocouple 27, and at its upper end is formed with a radially outwardly directed annular flange 2t). Disposed in spaced parallel relation with the annular flange 20 is a metallic heat conductive member 21 having a circular portion 22 (see FIGURE 2) and a coplanar projecting tab portion 23 formed with a circular aperture 24 surrounded by an integral upstanding collar 25. The upper end of the outer thermoelement 9 has a press fit within the aperture 24 and collar 25, and the bead 11 Welds said collar to the thermoelernent 9. The circular portion 22 of the conductive member 21 preferably has substantially the same diameter as the flange 20 and is axially aligned therewith. The space between the peripheral portions of the flange 20 and portion 22 of member 21 affords an annular horizontal flame port.

Fuel flowing upwardly through the burner body 18 and the orifice 19 impinges against the member 21 and flows radially outwardly in all directions, the velocity of the fuel being substantially reduced by the time it reaches the flame port, so that upon ignition of the fuel at the annular flame port, an annular flame is produced thereat, said flame surrounding the circular portion 22 of the member 21 and also wiping the-hot junction portion of the thermocouple 27. The member 21 not only functions as a flame shaping means for the pilot burner 2'6, but it also functions as a heat probe member conducting heat from the flame to the hot junction of the generator 27. It will be observed that the generator 27 is located on the :3 pilot burner 25 from the main burner 6, and that it is not subject to impingement by the flame of the main burner. The cycling of the main burner 6, therefore, has no substantial effect upon the electrical output of the generator 27.

FIGURES 3 and 4 illustrate another form of the invention which is adapted for operation in a horizontal position, as distinguished from the vertical position of the assembly shown in FIGURES l and 2. In FIGURES 3 and 4 the parts indicated by reference numerals bearing the suilix :2 correspond to parts of the form of the invention shown in FIGURES 1 and 2 indicated by the t1 will be obsame reference numerals without sufiix.

3 that the main body portion of the opposite side of the served in FIGURE burner body r80 extends horizontally and parallel with the thermocouple 27a. The outer end of the burner body 18a is right angularly curved toward the axis of the thermocouple 27 so that the orifice 19a is directed vertically and so that the circular flange Ztla is disposed in a horizontal plane. The heat conductive member 21a has its circular portion 22a in spaced parallel coaxial alignment with the flange Ztl'a, and has the extending tab portion 23a thereof right angularly bent into a vertical plane to receive the outer end of the thermocouple 27a in press fit relation within the aperture 24a and collar 25a as shown. The bead 11a welds the thermoelements 9a and Mia to each other and additionally welds the collar 25a onto the outer thermoelement 9a. The space between the peripheral portions of the flange 20a and portion 22a of member 21a forms a horizontally disposed annular flame port, and upon ignition of the fuel emitted therefrom, an annular flame is produced which surrounds the circular portion 22a and wipes the hot junction portion of the thermocoupple 27a.

As in the form of the invention shown in FIGURES 1 and 2, the heat conductive member 21a serves the dual functions of flame shaping means for the pilot burner 26a and heat probe means for the hot junction of the generator 27a. Further, it will be observed that the hot junction of the generator 27a is disposed on the opposite side of the plate member Zia from the burner 6a and is therefore not subjected to impingement by the flame of the main burner.

Having thus described two specific embodiments of the improved pilot burner-thermoelectric generator assembly, it is to be expressly understood that the illustrated forms of the invention were selected to facilitate the disclosure and are not intended to impose any unnecessary limitations on the claims or to confine the invention to a particular use. While the invention has been shown and described as embodied in structures utilizing non-aerated pilot burners, the invention can be embodied equally Well in structures utilizing aerated pilot burners, i.e. those in which primary air is mixed with the fuel within the burner body prior to emission from a flame port. Various other changes and modifications may be made in the disclosed embodiments to meet the requirements of practice, without in any manner departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the appended claims.

What is claimed as the invention is:

l. A composite pilot burner-thermoelectric generator assembly comprising a tubular burner body having fuel inlet means and terminating in a fuel discharge orifice, a thermoelectric generator fixed to said burner body in side-by-side relation, said generator comprising a tubular sheath member terminating at one end in a hot thermojunction portion, and a heat conductive member supported by a heat conductive fixed connection with said hot thermojunction portion at one side only of said member, said member having a substantially flat surface disposed adjacent and substantially normal to the axis of said fuel discharge orifice and having a central portion thereof in tersected by said axis for impingement thereagainst of a i stream of fuel emitted from said orifice, said member upon ignition of said fuel being operable as flame shaping means as Well as heat probe means for said generator.

2. A composite pilot burner-thermoelectric generator assembly comprising a tubular burner body having fuel inlet means and terminating in a substantially vertically directed fuel discharge orifice, a thermoelectric generator fixed to said burner body in side-by-side relation, said generator comprising a tubular sheath member terminating at one end in a hot thermojunction portion, and a heat conductive member supported by a heat conductive fixed connection with said hot thermojunction portion at one side only of said member, said member having a substantially flat horizontal surface disposed adjacent and substantially normal to the axis of said fuel discharge orifice and having a central portion thereof intersected by said axis for impingement thereagainst of a stream of fuel emitted from said orifice, said member upon ignition of said fuel being operable as flame shaping means as well as heat probe means for said generator.

3. A composite pilot burner-thermoelectric generator assembly comprising a tubular burner body having fuel inlet means and terminating in a circular flat end surface formed with a concentric fuel discharge orifice, a thermoelectric generator fixed to said burner body in side-by-side relation, said generator comprising a tubular sheath member terminating at one end in a hot thermojunction portion, and a heat conductive plate member supported by a heat conductive fixed connection with said hot thermojunction portion at one edge portion only of said member, said plate member having a circular main body portion of a size and shape corresponding to said burner body end surface disposed in spaced parallel coaxial relation with said end surface to define a narrow annular peripheral flame port, said plate member upon ignition of said fuel being operable as heat probe means for said generator.

'4. A composite non-aerated pilot burner-thermoelectric generator assembly comprising a base member, a tubular burner body projecting from said base member having fuel inlet means in said base member and terminating in a circular fiat horizontal end surface formed with a concentric fuel discharge orifice, a thermoelectric generator projecting from said base member in side-by-side relation with said burner body, said generator comprising a tubu lar sheath member terminating at one end in a hot thermo junction portion, and a horizontal heat conductive plate member supported by a heat conductive fixed connection with said hot thermojunction portion at one edge portion only of said member, said plate member having a circular main body portion of a size and shape corresponding to said burner body end surface disposed in spaced parallel coaxial relation with said end surface to define a narrow annular peripheral flame port, said plate member upon ignition of said fuel being operable as heat probe means for said generator.

5. A composite pilot burner-thermoelectric generator assembly comprising a vertically extending tubular burner body having fuel inlet means and terminating in a circular flat horizontal end surface formed with a concentric fuel discharge orifice, a vertically extending thermoelectric generator fixed to said burner body in side- -side relation, said generator comprising a tubular sheath member terminating at one end in a hot thermojunction portion, and a horizontal heat conductive plate member supported by a heat conductive fixed connection with said hot thermojunction portion at one edge portion only of said member, said plate member having a circular main body portion of a size and shape corresponding to said burner body end surface disposed in spaced parallel coaxial relation with said end surface to define a narrow annular horizontal peripheral flame port, said plate member upon ignition of said fuel being operable as heat probe means for said generator.

6. A composite pilot burner-thermoelectric generator assembly comprising a horizontally extending tubular burner body having fuel inlet means and having a curved end portion aifording said burner body an L-shaped configuration and terminating in a circular flat horizontal end surface formed with a concentric fuel discharge orifice, a horizontally extending thermoelectric generator fixed to said burner body in side-by-side relation, said generator comprising a tubular sheath member terminating at one end in a hot thermojunction portion, and a heat conductive plate member supported by a heat conductive fixed connection with said hot thermojunction portion at one edge portion only of said member, said plate member having a horizontal circular main body portion of a size and shape corresponding to said burner body end surface disposed in spaced parallel coaxial relation with said end surface to define a narrow annular horizontal peripheral flame port, said member upon ignition of said fuel being operable as heat probe means for said generator.

References Cited in the file of this patent UNITED STATES PATENTS 

